After the circumstances which had so humbled the imperial power, we are not astonished to see Sergius II. succeed Gregory IV. without waiting for the Emperor Lothaire’s consent. Yet this prince was so irritated at it, that he sent his son Louis into Italy at the head of an army. The terrified pontiff endeavoured to appease the young prince by means of honours and of homage. Louis examined into the election of Sergius, and ratified it in the midst of an assembly in which Sergius was judicially interrogated. His premature consecration was held valid only on condition that they should act more regularly for the future. The pope and the rest of the assembly took the oath of fidelity to the emperor.⁸³ This firmness of Lothaire upheld for a while the civil power, even in the states of Charles the Bald. This prince held a parliament at Epernai, in 846, to which the bishops were not admitted; in it were reprobated the canons which limited the rights of the king and of the lords, and measures were taken against the abuse of excommunications; ⁸³ Anast Bibl. de vit. Roman. Pontif. p. 352. In 847, Leo IV. was also consecrated before the emperor had confirmed the election; but they protested, that the ravages of the Saracens in the neighbourhood of Rome obliged them to act thus; and that nothing was meant derogatory to the fealty due to the head of the empire. Besides Leo IV. was the most venerated pontiff of the ninth century. He fortified Rome, built the part which bears the name of the Leonine city; and, without desiring to disturb other states, he laboured for the space of eight years, for the prosperity of that which he governed. The same praise cannot be bestowed on Nicholas I. who filled the chair of St. Peter from the year 858 to 867; but he was the pope of that century, which extended most the pontifical authority.